1. Field of the Invention
This invention relates to a novel hydroxyl group-containing (meth)acrylate oligomer, a method for the production thereof, a prepolymer from the oligomer mentioned above, a method for the production thereof, and a method for the use of the oligomer and the prepolymer. More particularly, this invention relates to a novel hydroxyl group-containing (meth)acrylate oligomer to be used for the production of polymers, copolymers, etc. useful in various applications, a method for the production of a hydroxyl group-containing (meth)acrylate oligomer from a hydroxyl group-containing (meth)acrylate as a raw material, a prepolymer from the oligomer, a method for the production of a prepolymer from the oligomer as a raw material, and a method for the use of the oligomer and prepolymer.
2. Description of Prior Art
The compound which contains a hydroxyl group and an acryloyloxy group or methacryloyloxy group in the molecular unit thereof is called a hydroxyl group-containing acrylate or methacrylate (hereinafter referred to collectively as a "hydroxyl group-containing (meth)acrylate" for short). Since the hydroxyl group-containing (meth)acrylate contains the two reactive functional groups, hydroxyl group and (meth)acryloyloxy group, in the molecular unit thereof, it is extensively used in the form of a homopolymer or a copolymer as in coating materials, adhesive agents, textile processing agents, and ultraviolet curing resins.
Typical examples of the hydroxyl group-containing (meth)acrylate heretofore known to the art are hydroxyalkyl (meth)acrylates such as hydroxyethyl acrylate and hydroxyethyl methacrylate, polyalkylene glycol mono(meth)acrylates, .epsilon.-caprolactone-adduct hydroxyethyl (meth)acrylate produced by the addition reaction of .epsilon.-caprolactone on hydroxyethyl (meth)acrylate, glycerol mono(meth)acrylate, and pentaerythritol tri(meth)acrylate. When any of the conventionally known hydroxyl group-containing (meth)acrylates is used alone, desired impartation of necessary functions cannot be attained. In the circumstance, the desirability of developing a hydroxyl group-containing (meth)acrylate possessing a novel structure has been finding growing recognition.
The urethane (meth)acrylate prepolymer, popularly called the urethane (meth)acrylate, which is obtained by the reaction of the hydroxyl group-containing (meth)acrylate with an isocyanate compound is an important component for the production of a thermosetting resin or a photosetting resin and is extensively used in coating materials, adhesive agents, inks, hard coats, resists, etc. The urethane (meth)acrylate prepolymer generally is produced by the reaction of a polyol and a polyisocyanate upon the hydroxyalkyl (meth)acrylate. Heretofore, numerous species of urethane (meth)acrylate prepolymer have been synthesized by varying the kinds and molecular weights of the raw materials, the mixing ratios of the raw materials, and the sequence of reactions involved. Most of the known prepolymers, however, are liquids of unusually high viscosity or solids and are required to be used in a form incorporating therein a large amount of a reactive diluent. None of these known prepolymers manifest all the curing properties such as the speed of curing, the rigidity of cured polymer produced, and the fastness of adhesion at satisfactory levels. Thus, the desirability of developing a urethane (meth)acrylate prepolymer possessing low viscosity and high curing speed and excelling in such curing properties as the rigidity of a cured polymer produced and the fastness of adhesion has been finding growing acceptance.
The carboxyl group-containing (meth)acrylate is an important component for the production of a thermosetting resin or photosetting resin and is finding extensive utility in numerous applications to coating materials, adhesive agents, inks, hard coats, resists, surface-improving agents, and dental cement. Generally, the carboxyl group-containing (meth)acrylate is produced by the reaction of the hydroxyl group-containing (meth)acrylate with a polybasic carboxylic acid or a polybasic carboxylic anhydride. For this purpose, the reaction with a polybasic carboxylic anhydride represented by the following reaction formula proves advantageous. ##STR2## wherein R.sup.10 stands for hydrogen atom or methyl group, R.sup.11 for a divalent organic group, and R.sup.12 for a carboxylic anhydride residue.
Heretofore, numerous species of carboxyl group-containing (meth)acrylates have been synthesized by varying the kinds of these raw materials. These carboxyl group-containing (meth)acrylates are used in a rich variety of applications as described above and, therefore, are required to possess structures suitable for such applications. In the circumstance, the desirability of developing a carboxyl group-containing (meth)acrylate possessing a structure unknown to the art and excelling in the curing properties has been finding growing approval.
Epoxy (meth)acrylates and hydroxyalkyl (meth)acrylates are well-known typical examples of the hydroxyl group-containing (meth)acrylate prepolymer. Such a hydroxyl group-containing (meth)acrylate prepolymer constitutes a component used for the production of a thermosetting resin or photosetting resin and is finding extensive utility in applications to coating materials, adhesive agents, inks, sealing agents, resists, and surface-modifying materials. Heretofore, numerous species of hydroxyl group-containing (meth)acrylate prepolymers have been synthesized by varying the kinds of raw materials and the reaction conditions involved. These hydroxyl group-containing (meth)acrylate prepolymers are used in a rich variety of applications as described above and they are required to possess peculiar structures suitable for these varying applications. Thus, the desirability of developing a hydroxyl group-containing (meth)acrylate prepolymer possessing a structure unknown to the art and excelling in the curing properties has been finding mounting approval.
The resins which are cured by radiations such as ultraviolet ray and electron beam excel the thermosetting resins which are cured by heat in terms of saving of resources, freedom from environmental pollution, and rapidity of curing and, therefore, find extensive utility. Generally, radiation-curing type resin compositions are compounded of such resin components as unsaturated polyesters and prepolymers of polyester (meth)acrylates, urethane (meth)acrylates, epoxy (meth)acrylates, and polyether (meth)acrylates and reactive diluent components such as mono(meth)acrylates like tetrahydrofurfuryl (meth)acrylate and phenoxyethyl (meth)acrylate and polyol poly(meth)acrylates like 1,6-hexanediol di(meth)acrylate and trimethylolpropane tri(meth)acrylate. Numerous species of radiation-curing resin compositions suitable for varying applications have heretofore been obtained by varying the mixing ratios of these components. By merely mixing these known components, however, it is difficult to obtain resin compositions which manifest curing speed and curing properties in balanced conditions. The desirability of developing a novel radiation-curing type resin composition manifesting curing speed and all the curing properties in balanced conditions has been finding growing approval.
An object of this invention, therefore, is to provide a novel hydroxyl group-containing (meth)acrylate oligomer, a method for the production of the oligomer, a prepolymer from the oligomer, a method for the production of the prepolymer, and a method for the use of the oligomer and the prepolymer.